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Refactored code to use SafeHandle where possible, this should fix potential resource leaks and make the code more clear.

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git-svn-id: http://svn.code.sf.net/p/greenshot/code/trunk@2429 7dccd23d-a4a3-4e1f-8c07-b4c1b4018ab4
This commit is contained in:
RKrom 2013-01-14 13:45:41 +00:00
commit 201ee7082e
7 changed files with 365 additions and 233 deletions
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238
GreenshotPlugin/UnmanagedHelpers/GDI32.cs
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@ -26,6 +26,13 @@ using Microsoft.Win32.SafeHandles;
namespace GreenshotPlugin.UnmanagedHelpers {
public static class GDIExtensions {
/// <summary>
/// Check if all the corners of the rectangle are visible in the specified region.
/// Not a perfect check, but this currently a workaround for checking if a window is completely visible
/// </summary>
/// <param name="region"></param>
/// <param name="rectangle"></param>
/// <returns></returns>
public static bool AreRectangleCornersVisisble(this Region region, Rectangle rectangle) {
Point topLeft = new Point(rectangle.X, rectangle.Y);
Point topRight = new Point(rectangle.X + rectangle.Width, rectangle.Y);
@ -38,103 +45,210 @@ namespace GreenshotPlugin.UnmanagedHelpers {
return topLeftVisible && topRightVisible && bottomLeftVisible && bottomRightVisible;
}
/// <summary>
/// Get a SafeHandle for the GetHdc, so one can use using to automatically cleanup the devicecontext
/// </summary>
/// <param name="graphics"></param>
/// <returns>SafeDeviceContextHandle</returns>
public static SafeDeviceContextHandle getSafeDeviceContext(this Graphics graphics) {
return SafeDeviceContextHandle.fromGraphics(graphics);
}
}
/// <summary>
/// Abstract class SafeObjectHandle which contains all handles that are cleaned with DeleteObject
/// </summary>
public abstract class SafeObjectHandle : SafeHandleZeroOrMinusOneIsInvalid {
[DllImport("gdi32", SetLastError = true)]
private static extern bool DeleteObject(IntPtr hObject);
protected SafeObjectHandle(bool ownsHandle) : base(ownsHandle) {
}
protected override bool ReleaseHandle() {
return DeleteObject(handle);
}
}
/// <summary>
/// A hbitmap SafeHandle implementation
/// </summary>
public class SafeHBitmapHandle : SafeHandleZeroOrMinusOneIsInvalid {
[SecurityCritical]
private SafeHBitmapHandle(): base(true) {
}
public class SafeHBitmapHandle : SafeObjectHandle {
[SecurityCritical]
private SafeHBitmapHandle() : base(true) {
}
[SecurityCritical]
public SafeHBitmapHandle(IntPtr preexistingHandle) : base(true) {
SetHandle(preexistingHandle);
}
protected override bool ReleaseHandle() {
return GDI32.DeleteObject(handle);
}
[SecurityCritical]
public SafeHBitmapHandle(IntPtr preexistingHandle) : base(true) {
SetHandle(preexistingHandle);
}
}
/// <summary>
/// A hRegion SafeHandle implementation
/// </summary>
public class SafeRegionHandle : SafeObjectHandle {
[SecurityCritical]
private SafeRegionHandle() : base(true) {
}
[SecurityCritical]
public SafeRegionHandle(IntPtr preexistingHandle) : base(true) {
SetHandle(preexistingHandle);
}
}
/// <summary>
/// A dibsection SafeHandle implementation
/// </summary>
public class SafeDibSectionHandle : SafeObjectHandle {
[SecurityCritical]
private SafeDibSectionHandle() : base(true) {
}
[SecurityCritical]
public SafeDibSectionHandle(IntPtr preexistingHandle) : base(true) {
SetHandle(preexistingHandle);
}
}
/// <summary>
/// A select object safehandle implementation
/// This impl will select the passed SafeHandle to the HDC and replace the returned value when disposing
/// </summary>
public class SafeSelectObjectHandle : SafeHandleZeroOrMinusOneIsInvalid {
[DllImport("gdi32", SetLastError = true)]
private static extern IntPtr SelectObject(IntPtr hDC, IntPtr hObject);
private SafeHandle hdc;
[SecurityCritical]
private SafeSelectObjectHandle() : base(true) {
}
[SecurityCritical]
public SafeSelectObjectHandle(SafeDCHandle hdc, SafeHandle newHandle) : base(true) {
this.hdc = hdc;
SetHandle(SelectObject(hdc.DangerousGetHandle(), newHandle.DangerousGetHandle()));
}
protected override bool ReleaseHandle() {
SelectObject(hdc.DangerousGetHandle(), handle);
return true;
}
}
public abstract class SafeDCHandle : SafeHandleZeroOrMinusOneIsInvalid {
protected SafeDCHandle(bool ownsHandle) : base(ownsHandle) {
}
}
/// <summary>
/// A CompatibleDC SafeHandle implementation
/// </summary>
public class SafeCompatibleDCHandle : SafeDCHandle {
[DllImport("gdi32", SetLastError = true)]
private static extern bool DeleteDC(IntPtr hDC);
[SecurityCritical]
private SafeCompatibleDCHandle() : base(true) {
}
[SecurityCritical]
public SafeCompatibleDCHandle(IntPtr preexistingHandle) : base(true) {
SetHandle(preexistingHandle);
}
public SafeSelectObjectHandle SelectObject(SafeHandle newHandle) {
return new SafeSelectObjectHandle(this, newHandle);
}
protected override bool ReleaseHandle() {
return DeleteDC(handle);
}
}
/// <summary>
/// A DeviceContext SafeHandle implementation
/// </summary>
public class SafeDeviceContextHandle : SafeDCHandle {
private Graphics graphics = null;
[SecurityCritical]
private SafeDeviceContextHandle() : base(true) {
}
[SecurityCritical]
public SafeDeviceContextHandle(Graphics graphics, IntPtr preexistingHandle) : base(true) {
this.graphics = graphics;
SetHandle(preexistingHandle);
}
protected override bool ReleaseHandle() {
graphics.ReleaseHdc(handle);
return true;
}
public SafeSelectObjectHandle SelectObject(SafeHandle newHandle) {
return new SafeSelectObjectHandle(this, newHandle);
}
public static SafeDeviceContextHandle fromGraphics(Graphics graphics) {
return new SafeDeviceContextHandle(graphics, graphics.GetHdc());
}
}
/// <summary>
/// GDI32 Helpers
/// </summary>
public static class GDI32 {
[DllImport("gdi32", SetLastError=true)]
public static extern bool BitBlt(IntPtr hObject,int nXDest,int nYDest, int nWidth,int nHeight,IntPtr hObjectSource, int nXSrc,int nYSrc, CopyPixelOperation dwRop);
public static extern bool BitBlt(SafeHandle hObject, int nXDest, int nYDest, int nWidth, int nHeight, SafeHandle hdcSrc, int nXSrc, int nYSrc, CopyPixelOperation dwRop);
[DllImport("gdi32", SetLastError=true)]
public static extern bool StretchBlt(IntPtr hdcDest, int nXOriginDest, int nYOriginDest, int nWidthDest, int nHeightDest, IntPtr hdcSrc, int nXOriginSrc, int nYOriginSrc, int nWidthSrc, int nHeightSrc, CopyPixelOperation dwRop );
public static extern bool StretchBlt(SafeHandle hdcDest, int nXOriginDest, int nYOriginDest, int nWidthDest, int nHeightDest, SafeHandle hdcSrc, int nXOriginSrc, int nYOriginSrc, int nWidthSrc, int nHeightSrc, CopyPixelOperation dwRop);
[DllImport("gdi32", SetLastError=true)]
public static extern IntPtr CreateCompatibleDC(IntPtr hDC);
public static extern SafeCompatibleDCHandle CreateCompatibleDC(SafeHandle hDC);
[DllImport("gdi32", SetLastError=true)]
public static extern bool DeleteDC(IntPtr hDC);
public static extern IntPtr SelectObject(SafeHandle hDC, SafeHandle hObject);
[DllImport("gdi32", SetLastError=true)]
public static extern bool DeleteObject(IntPtr hObject);
public static extern SafeDibSectionHandle CreateDIBSection(SafeHandle hdc, ref BitmapInfoHeader bmi, uint Usage, out IntPtr bits, IntPtr hSection, uint dwOffset);
[DllImport("gdi32", SetLastError=true)]
public static extern IntPtr SelectObject(IntPtr hDC,IntPtr hObject);
public static extern SafeRegionHandle CreateRectRgn(int nLeftRect, int nTopRect, int nRightRect, int nBottomRect);
[DllImport("gdi32", SetLastError=true)]
public static extern IntPtr CreateDIBSection(IntPtr hdc, ref BitmapInfoHeader bmi, uint Usage, out IntPtr bits, IntPtr hSection, uint dwOffset);
public static extern uint GetPixel(SafeHandle hdc, int nXPos, int nYPos);
[DllImport("gdi32", SetLastError=true)]
public static extern IntPtr CreateRectRgn(int nLeftRect, int nTopRect, int nRightRect, int nBottomRect);
[DllImport("gdi32", SetLastError=true)]
public static extern int GetClipBox(IntPtr hdc, out RECT lprc);
[DllImport("gdi32", SetLastError = true)]
public static extern uint GetPixel(IntPtr hdc, int nXPos, int nYPos);
[DllImport("gdi32", SetLastError = true)]
public static extern IntPtr CreateRoundRectRgn(int x1, int y1, int x2, int y2, int cx, int cy);
[DllImport("gdi32", SetLastError = true)]
public static extern int GetDeviceCaps(IntPtr hdc, DeviceCaps nIndex);
public static extern int GetDeviceCaps(SafeHandle hdc, DeviceCaps nIndex);
/// <summary>
/// StretchBlt extension for the graphics object
/// Doesn't work?
/// </summary>
/// <param name="target"></param>
/// <param name="source"></param>
public static void StretchBlt(this Graphics target, Bitmap sourceBitmap, Rectangle source, Rectangle destination) {
IntPtr hDCSrc = IntPtr.Zero;
IntPtr hDCDest = IntPtr.Zero;
try {
hDCDest = target.GetHdc();
hDCSrc = CreateCompatibleDC(hDCDest);
using (SafeHBitmapHandle hBitmapHandle = new SafeHBitmapHandle(sourceBitmap.GetHbitmap())) {
IntPtr pOrig = SelectObject(hDCSrc, hBitmapHandle.DangerousGetHandle());
StretchBlt(hDCDest, destination.X, destination.Y, destination.Width, destination.Height, hDCSrc, source.Left, source.Top, source.Width, source.Height, CopyPixelOperation.SourceCopy);
IntPtr pNew = SelectObject(hDCDest, pOrig);
}
} finally {
if (hDCSrc != IntPtr.Zero) {
DeleteDC(hDCSrc);
}
if (hDCDest != IntPtr.Zero) {
target.ReleaseHdc(hDCDest);
using (SafeDeviceContextHandle targetDC = target.getSafeDeviceContext()) {
using (SafeCompatibleDCHandle safeCompatibleDCHandle = CreateCompatibleDC(targetDC)) {
using (SafeHBitmapHandle hBitmapHandle = new SafeHBitmapHandle(sourceBitmap.GetHbitmap())) {
using (SafeSelectObjectHandle selectObject = safeCompatibleDCHandle.SelectObject(hBitmapHandle)) {
StretchBlt(targetDC, destination.X, destination.Y, destination.Width, destination.Height, safeCompatibleDCHandle, source.Left, source.Top, source.Width, source.Height, CopyPixelOperation.SourceCopy);
}
}
}
}
}
/// <summary>
///
/// Bitblt extension for the graphics object
/// </summary>
/// <param name="target"></param>
/// <param name="source"></param>
public static void BitBlt(this Graphics target, Bitmap sourceBitmap, Rectangle source, Point destination) {
IntPtr hDCSrc = IntPtr.Zero;
IntPtr hDCDest = IntPtr.Zero;
try {
hDCDest = target.GetHdc();
hDCSrc = CreateCompatibleDC(hDCDest);
using (SafeHBitmapHandle hBitmapHandle = new SafeHBitmapHandle(sourceBitmap.GetHbitmap())) {
IntPtr pOrig = SelectObject(hDCSrc, hBitmapHandle.DangerousGetHandle());
BitBlt(hDCDest, destination.X, destination.Y, source.Width, source.Height, hDCSrc, source.Left, source.Top, CopyPixelOperation.SourceCopy);
IntPtr pNew = SelectObject(hDCDest, pOrig);
}
} finally {
if (hDCSrc != IntPtr.Zero) {
DeleteDC(hDCSrc);
}
if (hDCDest != IntPtr.Zero) {
target.ReleaseHdc(hDCDest);
using (SafeDeviceContextHandle targetDC = target.getSafeDeviceContext()) {
using (SafeCompatibleDCHandle safeCompatibleDCHandle = CreateCompatibleDC(targetDC)) {
using (SafeHBitmapHandle hBitmapHandle = new SafeHBitmapHandle(sourceBitmap.GetHbitmap())) {
using (SafeSelectObjectHandle selectObject = safeCompatibleDCHandle.SelectObject(hBitmapHandle)) {
BitBlt(safeCompatibleDCHandle, destination.X, destination.Y, source.Width, source.Height, safeCompatibleDCHandle, source.Left, source.Top, CopyPixelOperation.SourceCopy);
}
}
}
}
}